Sewing machine ribbon tension guide



Nov. 22, 1960 R. E. SAYLES SEWING MACHINE RIBBON TENSION GUIDE FiledNov. 18, 1957 INVENTOR. Pdymo/mf. 54 V/e5 United States Patent SEWINGMACHINE RIBBON TENSION GUIDE Raymond E. Sayles, North Kansas City, Mo.,assignor to Pennway Garment Co., Kansas City, Mo., a corporation ofMissouri Filed Nov. 18, 1957, Ser. No. 697,116

1 Claim. (Cl. 242-155) The present invention relates to mechanism forcontrolling the unwinding of a strip, tape or the like from a rotatablesupply reel therefor, and more particularly to an attachment for asewing machine, the primary object being to provide releasableinstrumentalities for mamtaining the tape longitudinally taut betweenthe sewing mechanism of the machine and the tensioning mechanism thatforms a part of the aforementioned attachment.

It is the most important object of the present invention to providetensioning mechanism over which the tape is trained or looped andincluding a friction pulley whose rotation is retarded during operationof the attachment by a special spring bias assembly which exerts aconstant load on the pulley in accordance with the inherent tension ofthe spring itself, and which tension may be adjusted quickly and easilysimply by rotation of an adjusting nut on the mounting shaft for thepulley.

Still another object of the present invention is to provide novelrelease structure for relieving the pressure on the idler pulley,requiring the mere swinging of a lever to and from an operativeposition.

A further object of the present invention is to incorporate the releasestructure in the tensioning mechanism so that, upon swinging of theaforementioned lever, a cam reciprocates a release pin longitudinally ofthe shaft of the pulley and against a washer which normally retardsrotation of the pulley by clamping the same against a support for thereel and the pulley.

In the drawing:

Fig. 1 is a side elevational view of a sewing machine ribbon tensionguide made pursuant to my present invention.

Fig. 2 is a front elevational view thereof.

Fig. 3 is an enlarged, fragmentary, detailed, crosssectional view takenon line IIIIII of Fig. 1; and

Figs. 4 and S are transverse, cross-sectional views taken on lines IVIVand VV respectively of Fig. 3.

The attachment of the instant invention is illustrated in Figs. 1 and 2of the drawing operably mounted on a sewing machine fragmentarilyillustrated and broadly designated by the numeral 10. To this end thereis provided a Z-shaped support 12 having a pair of vertical stretches 14and 16, the latter of which supports a horizontal rod 18 upon which reel20 is rotatably mounted. Supply reel 20 for bias tape 22 or the like, isconfined between a pair of set collars 24 and 26 on the rod 18 andadjustment thereof determines the tension of spring 28 coiled on rod 18between reel 20 and set collar 26 to thereby retard rotation of reel 20.

From reel 20, tape 22 is trained under an idler roller 30, is thereuponlooped around an idler pulley 32, and then trained over a second idlerroller 34, whereupon tape 22 extends in a longitudinally taut stretch 36to pressure foot 38 forming a part of the sewing machine 10. Rollers 30and 34 are rotatably supported by an arm 40 secured to stretch 14 ofsupport 12 and extending laterally therefrom.

Idler pulley 32 includes a core 42 rotatable on a shaft "ice 44 which isin turn rigidly secured to stretch 14, together with a sleeve 46 on core42 and preferably made from rubber or other frictionable material.

Shaft 44 is provided with a longitudinal groove 48 within which isreciprocably mounted an elongated pin 50, and into which extends a lug52 forming a part of a washer 54 on shaft 44.

The outermost free end of the shaft 44 is provided with external screwthreads receiving an adjusting nut 56 and a spring 58 is coiled aboutthe shaft 44 between the nut 56 and the washer 54. One end of the spring58 bears against a collar 60 loosely threaded on shaft 44 between spring58 and washer 54. It is thus seen that spring 58 yieldably holds theidler pulley 32 clamped between washer 54 and one face 62 of stretch 14of support 12 and that the lug 52, slidable within the groove 48, holdsthe washer 54 against rotation.

A pin 64 extends from stretch 14 oppositely to the shaft 44 and isrotatably supported thereby. An elongated operating lever 66 is rigidlysecured to the pin 64, and a cam element 68 is attached to the pin 64for rotation therewith between lever 66 and the opposite face 70 ofstretch 14. Cam element 68 is in the nature of a small disc having thatface thereof proximal to pin 50 chamfered on one side of the pin 64 topresent a flat beveled surface 72.

In operation, lever 66 is positioned as illustrated in the drawing withsurface 72 of cam element 68 engaging pin 50, the latter thereby beingheld retracted by the action of spring 58. Accordingly, depending uponthe adjustment of nut 56, spring 58 exerts a constant load on the idlerpulley 32, thereby retarding rotation thereof and assuring that thestretch 36 of tape 22 is held taut as the tape 22 is Withdrawn from thesupply reel 20 by the action of the feeding mechanism (not shown) ofmachine 10 below foot 38.

When, however, it is desired to release the tension on idler pulley 32,the operator need merely swing the lever 66 either upwardly ordownwardly, thereby rotating the cam element 68 and forcing the pin 50inwardly along the groove 48 against the lug 52 of washer 54. Thisforces the washer 54 and the collar 60 toward the nut 56, compressingspring 58 and rendering the pulley 32 freely rotatable on the shaft 44.

The entire attachment may be removed from the machine 10 by looseningsetscrew 74, whereby the stretch 14 of support 12 may be withdrawn fromsocket member 76 on machine 10.

Having thus described the invention what is claimed as new and desiredto be secured by Letters Patent is:

The combination with a flexible tape fed from a rotatable wheel, tensionmechanism including an upright plate provided with an opening therein;an elongated shaft rigidly secured to said plate within the openingthereof and extending outwardly from one face of the latter; a corerotatably mounted on said shaft; a cylindrical sleeve of frictionablematerial rigid to and surrounding said core, said core and said sleeveeach having one extremity engaging said face of said plate, said shaftbeing provided with a longitudinal groove therein extending at least thelength of said sleeve and the thickness of said plate; an annular, metalwasher mounted on said shaft proximal to the opposite extremity of eachof said core and said sleeve and in engagement therewith, said washerbeing provided with a lug complementally received within said groove andhorizontally reciprocable therein; a collar mounted on said shaft at theend thereof spaced from said opening, said collar engaging said washer;a torsion nut threadably mounted on said end of said shaft; a springmounted on said shaft between said nut and said collar for biasing saidcore and said sleeve toward said plate; an elongated pin reciprocablyrelative to said plate; and a cam rigidIy mounted on said 373,760 rodbetween said lever and said plate, said cam engaging 2,625,127 said pinfor forcing the latter against said lug to release 2,653,559'

the pressure of said washer on saidextremity of" said 10 2,686,018

coreand said sleeve, and thereby lower the tension on said tape passing,over said sleeve.

References Cited in tlfe file of this patent UNITED STATES PATENTSTaylor et al. Nov. 22, 1887 Eckardt Jan. 13, 1953 PiClICCi .a-- 29,Courtney Aug. 10, 1954 New 9;

